In a manufacturing process of a semiconductor device, semiconductor substrates such as silicon wafers or compound semiconductor substrates have become larger in diameter and thinner in thickness. When a thin semiconductor substrate with a large diameter is transferred or subjected to a polishing process, there is a concern that a warpage or a crack may occur in the substrate. Therefore, target substrates have been reinforced by bonding support substrates such as glass substrates to the target substrates.
For example, International Publication WO2010/055730 discloses a method for bonding a target substrate and a support substrate in which the target substrate and the support substrate are held by an upper chuck and a lower chuck, respectively, and the upper chuck and the lower chuck are brought into close proximity with each other to press the target substrate and the support substrate. An adhesive is then applied on the surface of the target substrate or the support substrate such that both of the substrates are bonded by being pressed as described above.
Further, International Publication WO2010/055730 discloses a method for bonding a target substrate and a support substrate in which heating mechanisms are provided in an upper chuck and a lower chuck and the target substrate and the support substrate are heated.